Comparison of patients with primary Sjögren's syndrome with or without a positive interferon (IFN) type I signature
| Variable | N | IFN type I signature category | ||
|---|---|---|---|---|
| Positive | Negative | p Value | ||
| Demographics | ||||
| Female gender, n (%) | 69 | 34/38 (89) | 28/31 (90) | 0.908 |
| Age (years) | 69 | 56.7±12.5 | 59.5±13.3 | 0.376 |
| Disease duration (years) | 67 | 11.2±8.2 | 10.3±7.1 | 0.631 |
| Laboratory parameters, n (%) | ||||
| Anti-SSA, n (%) | 69 | 37/38 (97) | 21/31 (68) | 0.001 |
| Anti-Ro52, n (%) | 69 | 35/38 (92) | 19/31 (61) | 0.002 |
| Anti-Ro60, n (%) | 69 | 34/38 (89) | 13/31 (42) | <0.001 |
| Anti-SSB, n (%) | 69 | 32/38 (84) | 6/31 (19) | <0.001 |
| Rheumatoid factor (IE/ml) | 50 | 25 (0, 100) | 0 (0, 44) | 0.048 |
| C3 (g/l) | 46 | 1.06±0.20 | 1.27±0.33 | 0.012 |
| C4 (g/l) | 46 | 0.18 (0.13, 0.20) | 0.18 (0.14, 0.25) | 0.261 |
| IgG (g/l) | 68 | 16.10 (13.15, 18.55) | 11.60 (10.6, 15.00) | 0.001 |
| IgA (g/l) | 54 | 3.20 (2.18, 4.25) | 2.44 (1.69, 4.20) | 0.179 |
| IgM (g/l) | 54 | 1.22 (0.78, 1.97) | 1.36 (1.07, 1.67) | 0.876 |
| CRP (mg/l) | 61 | 1.0 (0.0, 5.5) | 3.0 (1.0, 7.0) | 0.068 |
| Hb (mmol/l) | 60 | 7.95 (7.58, 8.33) | 8.25 (7.78, 8.80) | 0.159 |
| Thrombocytes (×10E9/l) | 51 | 219.5 (199.3, 284.8) | 257 (221, 298) | 0.190 |
| Lymphocytes (×10E9/l) | 42 | 1.32±0.55 | 1.85±0.57 | 0.005 |
| Neutrophils (*10E9/l) | 41 | 3.09±1.18 | 4.42±1.78 | 0.014 |
| Medical treatment | ||||
| Pilocarpine, n (%) | 69 | 15/38 (39) | 12/31 (39) | 0.949 |
| Plaquenil, n (%) | 69 | 23/38 (61) | 17/31 (55) | 0.636 |
| Corticosteroids, n (%) | 69 | 3/38 (8) | 1/31 (3) | 0.412 |
Values are the mean±SD, median (25% quartile–75% quartile), or number (%) of patients, depending on whether the data are normally distributed or not, and whether the data are continuous or dichotomous. When the data followed normal distribution, the independent t test was conducted; otherwise the Mann–Whitney U test was conducted.
CRP, C-reactive protein; Hb, haemoglobin.